Neurostimulation systems that include implantable neurostimulation leads are used to treat chronic pain. Such systems may include an implantable pulse generator (IPG) from which one or more neurostimulating leads may extend to a length sufficient to provide therapeutic neurostimulation over desired regions of the body, such as regions of the head and back. The IPG may include a rechargeable battery, an antenna coil, and circuitry to control the neurostimulating leads. The IPG may also be configured for functionally connecting with an external radiofrequency unit that may be operable to perform various functions including recharging the rechargeable battery, diagnostically evaluating the IPG, and programming the IPG.
Improved techniques are desired for wirelessly charging/powering and communicating with such implantable neurostimulation systems and other body-implantable active devices, especially when such systems are implanted fully beneath the skin.